This invention relates to a runway judging process, specifically to a process for judging the contour or direction of the runway, based on image information obtained by taking a picture of the runway.
To drive a vehicle (e.g., automobile) automatically on a runway (e.g., road), it is necessary to recognize and judge the contour of the road in real time. In such a conceivable runway judging process, for example, a road ahead of an automobile is pictured by a TV camera, or the like, and the obtained data is image-processed.
FIGS. 1A-F show image displays of roads whose contours are to be judged. In FIGS. 1A-F, HL indicates a horizon, and RL and LL indicate the right and the left edges of the road respectively. SR represents a fork in the road. Contours of the road are a straight road (FIG. 1A), a curved road (FIG. 1B), a forked road (FIG. 1C), a branch divided from a main road FIG. 1D, and branches joined to main roads (FIGS. 1E and F).
It is not easy to recognize such variations of the contour of a runway.
In a conceivable process, for example, the edges corresponding to the sides RL, LL of a runway are extracted at the lower end of an image display, i.e., on the foreground of a road, and based on the extracted result, the sides RL, LL are traced upward on the image display, i.e., forward of the runway. But it is very difficult to recognize the branches exemplified in FIGS. 1C and D by this process.
When a recognition error takes place at the start or in the course of image data processing for the recognition, it becomes impossible to judge the contour of a road. Here it is assumed that the process in which the edges corresponding to the sides of a runway are extracted at the lower end of an image display of the road, i.e., in the foreground of the road, and based on the extracted result, the right and the left sides of the road are traced upward on the image display, i.e., forward of the road, is used. In this process, for example in FIG. 1D, when the edge corresponding to the left side of the road is discontinous, it is impossible to trace the left edge upward on the image display.
A first object of this invention is to provide a runway judging process which can judge variations of the contour of a runway easily and with high precision.
A second object of this invention is to provide a runway judging process which can judge variations of the contour of a runway with no errors and easily.